The following quote from Volume 3 of the Selected Works goes beyond economics or political economy into a philosophical conception of nature, which for me seems close to some sort of truth and offers explanatory power which can be applied to many phenomena:
“The great basic thought is that the world is not to be comprehended as a complex of ready-made things, but as a complex of processes, in which the things apparently stable…go through an uninterrupted process of becoming and passing away…For dialectical philosophy nothing is final, absolute, sacred. It reveals the transitory nature of everything and in everything; nothing can endure before it except the uninterrupted process of becoming and passing away, of endless ascendancy from the lower to the higher…The motion of matter is not merely crude mechanical motion, mere change of place, it is heat and light, electric and magnetic tension, chemical combination and dissociation, life and finally, consciousness.”
Having said all that, in my view there is no final ‘model’ of the things which we perceive, study and act upon. We can only view reality through the ‘software’ (our mind) that emerges from the ‘hardware’ (our brain and nervous system), so even the above conception, or any other, has its limits, and I find it helpful to be aware of this.